From the Wikipedia page [1]
The Readeption was the restoration of Henry VI of England to the throne of England. Edward, Earl of March had taken the throne as Edward IV in 1461. Henry had fled with some Lancastrian supporters and spent much of the next few years in hiding in the north of England or in Scotland, where there was still some Lancastrian support. Henry was captured in 1465 and was held as a prisoner in the Tower of London.
In 1469, Richard Neville, 16th Earl of Warwick rebelled against Edward along with Edward's younger brother, George, Duke of Clarence. After another failed rebellion in 1470 they both fled to France, where they encountered Margaret of Anjou, the wife of Henry VI. Warwick had played a huge role in helping Edward win the throne in 1461. However, after tense negotiations Warwick, Clarence and Margaret came to a deal whereby in return for French aid with an invasion, Warwick and Clarence would help restore Henry VI to the throne. Henry VI's son, Edward of Westminster, would be his heir as Prince of Wales, but if Westminster died then Clarence would become heir to the throne. This alliance was sealed by the marriage of Warwick's youngest daughter Anne Neville to Prince Edward.
Warwick's brother, John Neville, 1st Marquess of Montagu deserted Edward IV when Warwick invaded in 1470, and when Edward realised he could not stand against Warwick's army, he fled to his brother-in-law, Charles the Bold, Duke of Burgundy. Warwick entered London in triumph, and freed Henry VI from the Tower.
The Readeption of Henry VI took place on 3 October 1470. However, by this point Henry was too mentally feeble to rule unaided; for example, he had to be led by the hand when he paraded through London.
Henry's return to the throne did not last long. After gaining Burgundian support, Edward IV landed in Holderness in March 1471. He defeated Warwick in the Battle of Barnet on 14 April, in which Warwick was killed, and the Lancastrians in the Battle of Tewkesbury. Prince Edward was killed, the Beaufort family almost extinguished entirely and Queen Margaret captured. Edward IV entered London on 21 May. Henry VI died that night, probably killed on Edward's orders.
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